1. Field of the Invention
The present invention relates to a headlamp for an automobile of a reflector movable type in which a reflector mounted with a light source is inclinably supported by a lamp body by an aiming mechanism. More particularly, the present invention relates to a headlamp for an automobile in which the aiming mechanism may include an aiming screw rotatably supported by a screw insertion hole.
2. Description of the Related Art
As shown by FIG. 19, according to a conventional headlamp for an automobile of this kind, a reflector 2, integrally mounted with a light source, is supported by an aiming mechanism. In a conventional headlamp, the aiming mechanism is constituted by a ball and socket joint (not illustrated) constituting an aiming fulcrum, and two nut members (nut member screwed to aiming screw 4 is designated by notation 5) respectively screwed to two aiming screws (one aiming screw is designated by notation 4). With this configuration, the reflector is made extractable and retractable in an axial direction, on a front face side of a lamp body 1.
More specifically, the aiming screw 4 is rotatably supported by a screw insertion hole 1a and a screw portion 4a of the aiming screw 4 extended to a front side of the lamp body 1, and screwed with the nut member 5 attached to the reflector 2. By pivoting the aiming screw 4, the nut member 5 is extracted and retracted along the aiming screw 4, and the reflector 2 is inclined around an inclining axis connecting the ball and socket joint and the nut member screwed to other aiming screw to thereby enable adjustment of an optical axis of the lamp.
The aiming screw 4 is made of metal, and a rear end portion thereof is integrally formed with a crowned gear 7 so that aiming screw 4 can be operated to pivot by using a driver D. Further, the aiming screw 4 inserted into the screw insertion hole 1a from a rear side of the lamp body 1, is elastically supported and fixedly positioned in a front and rear direction by a push-on fix 8 made of metal.
Additionally, the screw insertion hole 1a, for rotatably supporting the aiming screw 4, is interposed with an O-ring 9 to thereby waterproof a rotational support portion of the aiming screw 4.
However, according to the above-described conventional technology, it is necessary to provide the O-ring 9 for ensuring waterproofing at the rotational support portion of the aiming screw 4. Also, the push-on fix 8 for positioning the aiming screw 4 in the front and rear direction is required. These two components help to increase the number of parts of the aiming mechanism, therefore, the assembly of the headlamp becomes more difficult. Particularly, interposing the push-on fix 8 at a predetermined position of the aiming screw 4 is considerably laborious because the pinching force by the push-on fix 8 is very strong.
Hence, in Japanese Patent Application Publication No. 2001-114014, as shown by FIGS. 20 and 21, the applicant proposed a structure in which a screw insertion hole 102 is constituted by a cylindrical member 100 formed at a lamp body 1A and having vertical slits 104 at a front end side of the cylindrical member 100 to form locking portions 106 at the front end side of the cylindrical member 100. These locking portions 106 deform elastically when the aiming screw is inserted into the screw insertion hole 102 from a rear side of the lamp body 1A. That is, the aiming screw pushes to expand the locking portions 106 on the front end side of the cylindrical portion to an outer side in the radial direction, wherein a supported portion of the aiming screw is contained in the screw insertion hole and the aiming screw can simply be positioned fixedly to the screw insertion hole 102.
However, although the aiming screw can simply be positioned fixedly to the screw insertion hole 102, when the aiming screw is inserted into the screw insertion hole 102, a considerable pressing force is needed to push, and thereby widen, the comparatively thick locking portions 106 on the front end side of the cylindrical portion. As such, more time is required to mount the aiming screw, and also, a pressing machine having sufficient pressing force is needed for inserting the aiming screw.
Further, although the cylindrical portion 100 is integrally formed with the lamp body 1A, since the shape of the front end side of the cylindrical portion 100 (shape of locking portion 106) is complicated, forming dies to make this structure is also complicated due to the difficulty in machining of the forming faces of the dies. This also leads to increased time and cost for manufacturing the dies.
The present invention has been carried out in view of the above-described problems of the conventional technology and it is an object of the invention to provide a headlamp for an automobile of a reflector movable type wherein the mounting of an aiming screw into a screw insertion hole is performed smoothly and simply without using a push-on fix or requiring the use of complicated dies.
In order to achieve the above-described object, according to a first aspect of the invention, there is provided a reflector moveable type headlamp for an automobile which comprises:
a lamp body;
a light source;
a reflector positioned to reflect light originating from the light source; and
an aiming mechanism interposed between the lamp body and the reflector and operable to inclinably support and move the reflector relative to the lamp body;
wherein the aiming mechanism includes:
a screw insertion hole including a cylindrical portion; and
an aiming screw operable to move the reflector by pivoting the aiming screw, the aiming screw including a supported portion supported by the screw insertion hole, a male screw portion forward from the supported portion, and a pivotal movement operating force transmitted portion rearward from the supported portion,
wherein a front end side of the supported portion includes an elastic locking portion operable to pass through the screw insertion hole by being deformed elastically to an inner side in a radius direction and engage with a peripheral edge portion on a front end side of the screw insertion hole to prevent the aiming screw from drawing in a rear direction, and a rear end side of the supported portion is integrally formed with an elastic rib brought into press contact with a peripheral edge portion on a rear end side of the screw insertion hole to fixedly position the aiming screw.
Accordingly, when the aiming screw is pushed into the screw insertion hole from a rear face side of the lamp body, the elastic locking portion on the front end side of the supported portion of the aiming screw is pushed by the peripheral edge portion on the rear end side of the screw insertion hole and an inner peripheral face of the hole to elastically deform to contract to the inner side in the radial direction and slide in the screw insertion hole.
Further, when the supported portion of the aiming screw is pushed into the screw insertion hole by a force equal to or larger than a spring force which the elastic rib receives from the peripheral edge portion of the rear end side of the screw insertion hole, and when the elastic locking portion passes through the screw insertion hole, the elastic locking portion recovers to an outer side in the radial direction and engages with a peripheral edge portion on the front end side of the screw insertion hole to thereby prevent the aiming screw from drawing in the rear direction. Also, the elastic rib on the rear end side of the supported portion is brought into a press contact state with the peripheral edge portion on the rear end side of the screw insertion hole to thereby fixedly position the aiming screw to the screw insertion hole in an axial direction.
Whereas according to Japanese Patent Application Publication No. 2001-114014 (refer to FIGS. 20, 21), when the aiming screw is inserted into the screw insertion hole, a large aiming screw pushing force is required for pushing the comparatively thick-walled locking portion on the front end side of the cylindrical portion to expand and elastically deform to the outer side of the radius direction. According to the first aspect of the present invention, the elastic locking portion formed at the supported portion of the aiming screw is easy to elastically deform to the inner side in the radial direction and accordingly, the aiming screw pushing force may be small. That is, a section modulus of a cross face of the elastic locking portion formed on the side of the aiming screw is smaller than a section modulus of a cross face of the elastic locking portion formed at the cylindrical portion in Japanese Patent Application Publication No. 2001-114014. As such, the elastic locking portion formed at the supported portion is made to deform elastically within the screw insertion hole.
Further, in the present invention, either of the elastic rib or the lamp body (cylindrical portion) may be made of synthetic resin and at a sliding contact portion between the elastic rib and the peripheral edge portion of the screw insertion hole, the elastic rib and the lamp body are ensured to slide and not hamper pivotal movement of the aiming screw. Also, the elastic rib made of synthetic resin is less deteriorated by water than a conventional O-ring made of rubber.
Finally, the screw insertion hole constituted by the cylindrical portion of the present invention is simpler in configuration than the cylindrical portion in Japanese Patent Application Publication No. 2001-114014 and therefore, forming dies and shaping the forming face are also simplified.
According to a second aspect of the present invention, there is provided the reflector movable type headlamp for an automobile, wherein the elastic locking portions include locking pieces in the shape of a tongue piece provided at a plurality of locations at equal intervals in a peripheral direction of the supported portion and extended in a rear direction.
Therefore, in operation, a plurality of the locking pieces in the shape of the tongue piece are uniformly deformed to the inner side and the supported portion is smoothly inserted into the screw insertion hole.
Further, the plurality of locking pieces in the shape of the tongue piece are uniformly brought into press contact with positions of the peripheral edge portions on the front end side of the screw insertion hole at equal intervals in the peripheral direction to thereby guarantee smooth pivotal movement of the aiming screw.
In addition, particularly, when the elastic locking portions are constituted by a pair of the opposed locking pieces in the shape of the tongue piece, divided dies having a parting line crossing outer side faces of the locking pieces in the shape of the tongue piece in the vertical direction may be used to form the supported portion, and thereby facilitate forming the supported portion.
Further, the locking piece in the shape of the tongue piece can be formed to be in an L-like shape in a vertical section thereof and made thick-walled toward a front end side of a horizontal extended portion thereof.
When constituted in this way (when the locking piece in the shape of the tongue piece is formed to be thick-walled toward the front end side of the horizontal extended portion), in inserting the aiming screw (supported portion) into the screw insertion hole, the locking piece in the shape of the tongue piece, an inserted side of which is converging, is brought into contact with the peripheral edge portion of the screw insertion hole to thereby elastically deform to the inner side in the radial direction and can therefore invade smoothly inside of the screw insertion hole. Further, since the front end portion of the locking piece in the shape of the tongue piece is thick-walled, an area of the locking piece in the shape of the tongue piece engaging with the front end face of the cylindrical portion is large and accordingly, the locking piece in the shape of the tongue piece becomes difficult to detach from the front end face of the cylindrical portion.
According to a third aspect of the present invention, the elastic rib may be formed in a skirt-like shape.
In operation, the skirt-like elastic rib is uniformly brought into press contact with a total periphery of the peripheral edge portion on the rear end side of the screw insertion hole to thereby support the aiming screw without play and also hamper or prevent water from invading the screw insertion hole.
According to a fourth aspect of the present invention, the pivotal movement operating force transmitted portion may be constituted by a crowned gear directing teeth thereof in the front direction, the screw insertion hole may be constituted by the cylindrical portion penetrating the lamp body in the front and rear direction and extended in the front and rear direction, and an outer peripheral face of a rear extended portion of the cylindrical portion may be provided with a tool positioning contact portion for positioning a front end portion of a tool used to pivot the crowned gear.
In operation, by prolonging a length of the screw insertion hole in the front and rear direction, the aiming screw can be held without play and waterproof performance at a rotational support portion of the aiming screw is also promoted.
Further, when a front end portion of the tool, such as driver arranged along the lamp body, is brought into contact with the tool positioning contact portion for pivoting the aiming screw, teeth of the tool may be held in mesh with teeth of the crowned gear portion to thereby facilitate and ensure pivotal operation of the aiming screw.
According to a fifth aspect of the present invention, an outer peripheral face of the supported portion may be integrally formed with an elastic waterproof rib in a ring-like shape brought into sliding contact with an inner peripheral face of the screw insertion hole.
In operation, the elastic waterproof rib in the ring-like shape formed at the supported portion of the aiming screw and brought into sliding contact with the inner peripheral face of the screw insertion hole, is held by the inner peripheral face of the screw insertion hole in a press contact state to thereby waterproof or provide a seal at the rotational support portion of the aiming screw.
Further, the waterproof rib may be made of synthetic resin and provided with elasticity and flexibility and accordingly, elastically deformed when the supported portion of the aiming screw is inserted into the cylindrical portion (screw insertion hole). This configuration does not hamper integration of the aiming screw into the screw insertion hole and the sliding contact portion between the elastic waterproof rib and the inner peripheral face of the screw insertion hole does not hamper pivotal movement of the aiming screw.
Further, a waterproof rib made of synthetic resin is less deteriorated by water than an O-ring made of rubber.
According to a sixth aspect of the present invention, both the entire aiming screw or the cylindrical portion may be integrally formed with synthetic resin. In operation, for example, since the entire aiming screw is formed by synthetic resin, it is light-weighted.
According to a seventh aspect of the present invention, the aiming screw is screwed with a nut member constituting an aiming mechanism constituent member mounted to the reflector and the nut member is carried by a nut sliding guide formed integrally with the lamp body and extended in parallel with the aiming screw.
In operation, the nut member constituting an aiming point is carried by the nut sliding guide integrally formed with the lamp body and therefore, weight of the reflector is not operated to the screw insertion hole constituting the rotational supporting portion of the aiming screw.